1. Field of the Invention
The present invention relates to an image reader for optically and electronically sensing and reading an image, which is recorded on an image-recording medium, such as a photographic transparency or the like, by illuminating the image-recording medium with a light source and by scanning the illuminated image-recording medium with a line image sensor.
2. Description of the Related Art
Such an image reader per se is well known, and is used in peripheral equipment associated with an image-processing computer for retrieving a recorded or photographed image from a photographic transparency. The image reader includes a solid-state line image sensor, such as a CCD (charge-coupled device) image sensor, a suitable light source for illuminating the photographic transparency, and an optical system for focusing an illuminated optical image on a linear light-receiving surface of the CCD line image sensor. The linear light-receiving surface of the image sensor is defined by a plurality of CCD elements aligned with each other, which converts the focused optical image into a single-line of image-pixel signals.
A reading of the recorded image from the photographic transparency is performed by intermittently and relatively moving the line image sensor with respect to the photographic transparency such that the recorded image is scanned with the line image sensor. At each scanning step, a single-line of image-pixel signals is output from the CCD line image sensor, and a frame of image-pixel signals is obtained from the line image sensor when the scanning of the recorded image with the line image sensor is completed. The frame of image-pixel signals is converted into a frame of digital image-pixel signals, and is stored in a suitable memory medium, such as an IC cord, a floppy disc or the like. If necessary, the frame of digital image-pixel signals may be directly fed from the image reader to an image-processing computer.
Of course, in the image reader, a scanning range, over which the recorded image is scanned with the line image sensor, is previously defined such that a standardized image-recording frame area of the photographic transparency is fully covered by the scanning range.
Recently, a new type of camera has been developed, in which an optical object can be selectively photographed on a photographic film in either a regular format mode or a panorama format mode. Of course, when the regular format mode is selected, the whole of an image-recording frame area of the photographic film is utilized as a photographing-area in a conventional manner. On the contrary, when the panorama format mode is selected, a restricted part of the standardized image-recording frame area of the photographic film is utilized as a photographing-area. Namely, in the panorama format mode, lower and upper side zones of the image-recording frame area are masked such that a panorama or wide image-recording frame area is defined therebetween, and an optical object is photographed on the panorama image-recording frame area.
By using the aforementioned image reader, it is possible to optically and electronically read a photographed image from each of the photographic transparencies obtained from a photographed and developed film including regular-formatted images and panorama-formatted images. As mentioned above, the image reader is designed such that a standardized image-recording frame area of the photographic transparency is fully scanned with the CCD line image sensor. Thus, when a panorama-formatted image is read by the image reader, the whole of the standardized image-recording frame area of the photographic transparency must be fully scanned with the line image sensor even if the panorama-formatted image is recorded on only the panorama image-recording frame area forming a part of the standardized image-recording frame area. In other words, the masked and unexposed lower and upper side zones of the standardized image-recording frame area must be uselessly scanned with the line image sensor whenever the panorama-formatted image is read by the image reader. Of course, the useless scanning operation should be prevented before a reading-time, over which the panorama-formatted image is read by the image reader, can be shortened.
Further, when a frame of digital image-pixel signals, obtained from a photographic transparency carrying a panorama formatted image, is stored in a memory medium, such as an IC memory cord, a floppy disc or the like, a capacity of the memory medium is uselessly consumed because the meaningless pixel-image signals, derived from the masked and unexposed silo lower and upper side zones of the standardized image-recording frame area, must be stored in the memory medium, together with effective image-pixel signals, derived from the panorama formatted image.
Therefore, an object of the present invention is to provide an image reader which is constituted such that a panorama-formatted image can be effectively read from a panorama image-recording frame area, forming a part of a standardized image-recording area of a photographic transparency, without scanning the whole of the standardized image-recording area with a line image sensor.
In accordance with the present invention, there is provided an image reader which comprises: a line image sensor that optically and electronically senses and reads by scanning an image-recording area of a recording medium with the line image sensor; a regular-reading controller that makes the line image sensor execute a regular reading operation such that the image-recording area of the recording medium is scanned at a regular-reading-scan-pitch with the line image sensor; a pre-reading controller that makes the line image sensor execute a pre-reading operation, prior to the execution of the regular-reading operation, such that the image-recording area of the recording medium is scanned at a pre-reading-scan-pitch, rougher than the regular-reading-scan-pitch, with the line image sensor; a determiner that determines whether an image to be read from the recording medium is recorded on a whole of the image-recording area or a restricted area of the image-recording area on a basis of a series of image-pixel data obtained by the execution of the pre-reading operation; and a regular-reading regulator that regulates the execution of the regular-reading operation such that the restricted area of the image-recording area is scanned with the line image sensor when it is determined by the determiner that the image to be read from the recording medium is recorded on the restricted area of the image-recording area.
The recording medium may be a photographic transparency object having a standardized image-recording frame area, and the restricted area may be a panorama image-recording frame area defined on the standardized image-recording frame area.
In accordance with a first aspect of the present invention, the determiner comprises: a detector that detects two scanning-lines, which respectively correspond to two single-lines of image-pixel data, respectively, obtained by the execution of the pre-reading operation, defining a minimum range in which the restricted area of the image-reading area falls; a first calculator that calculates one of the two scanning-lines as a scan-start-position for the restricted area of the image-recording area on a basis of the pre-reading-scan-pitch and the regular-reading-scan-pitch when the two scanning-lines are detected by the detector; and a second calculator that calculates another of the two scanning-lines as a scan-end-position for the restricted area of the image-recording area on a basis of the pre-reading-scan-pitch and the regular-reading-scan-pitch when the two scanning-lines are detected by the detector. The regular-reading regulator comprises: a first driver controller that relatively and continuously moves the recording medium with respect to the line image sensor, without being intermitted, until the line image sensor is positioned at the scan-start-position; and a second driver controller that relatively and intermittently moves the recording medium with respect to the line image sensor at the regular-reading-scan-pitch from the scan-start-position to the scan-end-position.
In accordance with a second aspect of the present invention, the image reader further comprises a memory medium that temporarily stores the series of image-pixel data obtained by the execution of the pre-reading operation. In this case, the determiner comprises: a data reader that successively reads a single-line of image-pixel data from the memory medium; a calculator that calculates an average data from the single-line of image-pixel data, successively read from the memory medium; and a comparator that compares the calculated average data with a predetermined threshold data to determine whether there is a drastic change between two consecutive single-lines of image-pixel data obtained by the execution of the pre-reading operation, whereby it is determined that there is a boundary, defining the restricted image-recording area, between two consecutive scanning-lines, corresponding the two consecutive single-lines of image-pixel data obtained by the execution of the pre-reading operation, when it is determined by the comparator that there is the drastic change between the two consecutive single-lines of image-pixel data.
In the second aspect of the present invention, the determiner may further comprise: a first calculator that calculates a trailing one of the two consecutive scanning-lines as a scan-start-position for the restricted area of the image-recording area on a basis of the pre-reading-scan-pitch and the regular-reading-scan-pitch when the trailing one of the two consecutive scanning-lines is out of the restricted area of the image-recording area; and a second calculator that calculates a leading one of the two consecutive scanning-lines as a scan-end-position for the restricted area of the image-recording area on a basis of the pre-reading-scan-pitch and the regular-reading-scan-pitch when the leading one of the two consecutive scanning-lines is out of the restricted area of the image-recording area. In this case, the regular-reading regulator comprises: a first driver controller that relatively and continuously moves the recording medium with respect to the line image sensor, without being intermitted, until the line image sensor is positioned at the scan-start-position; and a second driver controller that relatively and intermittently moves the recording medium with respect to the line image sensor at the regular-reading-scan-pitch from the scan-start-position to the scan-end-position.
In accordance with a third aspect of the present invention, there is provided an image reader which comprises: a line image sensor that optically and electronically senses and reads by scanning an image-recording area of a recording medium with the line image sensor; a regular-reading controller that makes the line image sensor execute a regular reading operation such that the image-recording area of the recording medium is scanned at a regular-reading-scan-pitch with the line image sensor; a pre-reading controller that makes the line image sensor execute a pre-reading operation, prior to the execution of the regular-reading operation, such that the image-recording area of the recording medium is scanned at a pre-reading-scan-pitch with the line image sensor; and a determiner that determines whether an image to be read from the recording medium is recorded on a whole of the image-recording area or a restricted area of the image-recording area on a basis of a series of image-pixel data obtained by the execution of the pre-reading operation. The determiner comprises: a detector that detects two scanning-lines, which respectively correspond to two single-lines of image-pixel data, respectively, obtained by the execution of the pre-reading operation, defining a minimum range in which the restricted area of the image-reading area falls; a first calculator that calculates one of the two scanning-lines as a scan-start-position for the restricted area of the image-recording area on a basis of the pre-reading-scan-pitch and the regular-reading-scan-pitch when the two scanning-lines are detected by the detector; and a second calculator that calculates another of the two scanning-lines as a scan-end-position for the restricted area of the image-recording area on a basis of the pre-reading-scan-pitch and the regular-reading-scan-pitch when the two scanning-lines are detected by the detector. The regular-reading controller that relatively and continuously moves the recording medium with respect to the line image sensor, without being intermitted, until the line image sensor is positioned at the scan-start-position, and that relatively and intermittently moves the recording medium with respect to the line image sensor at the regular-reading-scan-pitch from the scan-start-position to the scan-end-position, when it is determined by the determiner that the image to be read from the recording medium is recorded on the restricted area of the image-recording area.